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Ray
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Free Radic Biol Med 2001 Feb 15;30(4):433-446
Flavonoids protect neuronal cells from oxidative stress by three distinct
mechanisms.
Ishige K, Schubert D, Sagara Y
The Salk Institute for Biological Studies, La Jolla, CA, USA
[Record supplied by publisher]
Flavonoids are a family of antioxidants found in fruits and vegetables as well
as in popular beverages such as red wine and tea. Although the physiological
benefits of flavonoids have been largely attributed to their antioxidant
properties in plasma, flavonoids may also protect cells from various insults.
Nerve cell death from oxidative stress has been implicated in a variety of
pathologies, including stroke, trauma, and diseases such as Alzheimer's and
Parkinson's. To determine the potential protective mechanisms of flavonoids in
cell death, the mouse hippocampal cell line HT-22, a model system for oxidative
stress, was used. In this system, exogenous glutamate inhibits cystine uptake
and depletes intracellular glutathione (GSH), leading to the accumulation of
reactive oxygen species (ROS) and an increase in Ca(2+) influx, which ultimately
causes neuronal death. Many, but not all, flavonoids protect HT-22 cells
and rat
primary neurons from glutamate toxicity as well as from five other oxidative
injuries. Three structural requirements of flavonoids for protection from
glutamate are the hydroxylated C3, an unsaturated C ring, and
hydrophobicity. We
also found three distinct mechanisms of protection. These include increasing
intracellular GSH, directly lowering levels of ROS, and preventing the
influx of
Ca(2+) despite high levels of ROS. These data show that the mechanism of
protection from oxidative insults by flavonoids is highly specific for each
compound.
PMID: 11182299
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Ray Strand
Prairie Sky Design
-----------------( on the Edge of the Prairie Abyss )---------------
when the sky is clear
the ground is visible
49/dx PD 2 yrs/40? onset/retired
